package com.g2room.myuall.util;

import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

/**
 * 使用AES加密与解密
 *
 */
public class EncryptUtil {
	/** 数据库密码加密的私钥 */
	public static final String KEY_DBPWD = "ksnxcu17s621nGs2a@";
	
	private static SecretKey getKey(String strKey) {
		// WINDOW
//		 try {         
//	            KeyGenerator _generator = KeyGenerator.getInstance( "AES" );
//	            _generator.init(128, new SecureRandom(strKey.getBytes()));
//	                return _generator.generateKey();
//	        }  catch (Exception e) {
//	        	e.printStackTrace();
//	             throw new RuntimeException( " 初始化密钥出现异常 " );
//	        }
		 
		// LINUX
		try {           
	          KeyGenerator generator = KeyGenerator.getInstance( "AES" );  
	           SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG" );  
	          secureRandom.setSeed(strKey.getBytes());  
	          generator.init(128,secureRandom);  
              return generator.generateKey();
	      }  catch (Exception e) {
	    	  e.printStackTrace();
	           throw new RuntimeException( " 初始化密钥出现异常 " );  
	      }  
	}
	/**
	 * 加密
	 * 
	 * @param content 需要加密的内容
	 * @param password  加密密码
	 * @return
	 */
	public static String encrypt(String content, String password) {
		String rs = null;
		try {
//			KeyGenerator kgen = KeyGenerator.getInstance("AES");
//			kgen.init(128, new SecureRandom(password.getBytes()));
//			SecretKey secretKey = kgen.generateKey();
			SecretKey secretKey = getKey(password);
			byte[] enCodeFormat = secretKey.getEncoded();
			SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
			Cipher cipher = Cipher.getInstance("AES");// 创建密码器
			byte[] byteContent = content.getBytes("utf-8");
			cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化
			byte[] result = cipher.doFinal(byteContent);
			rs = parseByte2HexStr(result);
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			e.printStackTrace();
		} catch (BadPaddingException e) {
			e.printStackTrace();
		}
		return rs;
	}

	/**
	 * 解密
	 * 
	 * @param content 待解密内容
	 * @param password 解密密钥
	 * @return
	 */
	public static String decrypt(String content, String password) {
		String rs = null;
		try {
//			KeyGenerator kgen = KeyGenerator.getInstance("AES");
//			kgen.init(128, new SecureRandom(password.getBytes()));
//			SecretKey secretKey = kgen.generateKey();
			
			SecretKey secretKey = getKey(password);
			byte[] enCodeFormat = secretKey.getEncoded();
			SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
			Cipher cipher = Cipher.getInstance("AES");// 创建密码器
			cipher.init(Cipher.DECRYPT_MODE, key);// 初始化
			//byte[] decryptFrom = parseHexStr2Byte(encryptResultStr); 
			byte[] result = cipher.doFinal(parseHexStr2Byte(content));
			
			rs = new String(result);
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			e.printStackTrace();
		} catch (BadPaddingException e) {
			e.printStackTrace();
		}
		return rs;
	}
	
	/**
	 * 将二进制转换成16进制
	 * 
	 * @param buf
	 * @return
	 */
	public static String parseByte2HexStr(byte buf[]) {
		StringBuffer sb = new StringBuffer();
		for (int i = 0; i < buf.length; i++) {
			String hex = Integer.toHexString(buf[i] & 0xFF);
			if (hex.length() == 1) {
				hex = '0' + hex;
			}
			sb.append(hex.toUpperCase());
		}
		return sb.toString();
	}

	/**
	 * 将16进制转换为二进制
	 * 
	 * @param hexStr
	 * @return
	 */
	public static byte[] parseHexStr2Byte(String hexStr) {
		if (hexStr.length() < 1)
			return null;
		byte[] result = new byte[hexStr.length() / 2];
		for (int i = 0; i < hexStr.length() / 2; i++) {
			int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
			int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2),
					16);
			result[i] = (byte) (high * 16 + low);
		}
		return result;
	}
	

	public static void main(String[] strs) {
		
		String content = "6EB57787A28EAA1A250D2E115A98ECD7";  
		String password = KEY_DBPWD;  
//		//加密  
//		System.out.println("加密前：" + content);  
//		content = encrypt(content, password);  
//		System.out.println("加密后：" + content);  
		//解密  
		content = decrypt(content,password);  
		System.out.println("解密后：" + content); 
		
	}
}
